Sediment pore water distribution coefficients of PCB congeners in enriched black carbon sediment

More than 2300 sediment pore water distribution coefficients (K-PCBi (ds)) of 93 polychlorinated biphenyls (PCBs) were measured and modeled from sediments from Indiana Harbor and Ship Canal. K-PCBi (ds) were calculated from previously reported bulk sediment values and newly analyzed pore water. PCBs in pore waters were measured using SPME PDMS-fiber and Sigma PCB ranged from 41 to 1500 ng L-1. The resulting K-PCBi ds were similar to 1 log unit lower in comparison to other reported values. A simple model for the K-PCBi (d) consisted of the product of the organic carbon fraction and the octanol water partition coefficient and provided an excellent prediction for the measured values, with a mean square error of 0.09 +/- 0.06. Although black carbon content is very high in these sediments and was expected to play an important role in the distribution of PCBs, no improvement was obtained when a two-carbon model was used. (C) 2013 Elsevier Ltd. All rights reserved.